Pulse oximetry is a noninvasive procedure for measuring the oxygen saturation level of arterial blood, an important parameter in critical patient care applications. Pulse oximeters generally perform a spectral analysis of the pulsatile component of arterial blood in order to determine the relative concentration of oxygenated hemoglobin, the major oxygen carrying constituent of blood, to depleted hemoglobin. A pulse oximetry system includes of a sensor and a monitor. The sensor includes emitters generally having at least one red light emitting diode (LED) and at least one infrared LED that project light through blood vessels and capillaries underneath a tissue site, such as a fingernail bed. The sensor also has a detector typically consisting of a photodiode positioned opposite the LEDs so as to detect the emitted light as it emerges from the tissue site. Pulse oximeters have gained rapid acceptance in a wide variety of medical applications, including surgical wards, intensive care units, general wards and home care by providing early detection of decreases in the arterial oxygen supply and thereby, reducing the risk of accidental death and injury.